fix: update MissingVendor usages for struct-variant after merge

Latest main added new `MissingVendor` references (the error_code and
operator_mitigation match arms, plus rpc/api-model tests) that still treated it
as a unit variant. Update them for the `MissingVendor { observed }` struct
variant introduced earlier on this branch.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: Sinck

crates/api-model/src/site_explorer/mod.rs

@@ -1317,7 +1317,7 @@ impl OperatorError for EndpointExplorationError {
                 ErrorCode::nico(SiteExplorer, 120)
             }
             EndpointExplorationError::MissingRedfish { .. } => ErrorCode::nico(SiteExplorer, 121),
-            EndpointExplorationError::MissingVendor => ErrorCode::nico(SiteExplorer, 122),
+            EndpointExplorationError::MissingVendor { .. } => ErrorCode::nico(SiteExplorer, 122),
             EndpointExplorationError::RedfishError { .. } => ErrorCode::nico(SiteExplorer, 130),
             EndpointExplorationError::VikingFWInventoryForbiddenError { .. } => {
                 ErrorCode::nico(SiteExplorer, 131)
@@ -1349,7 +1349,7 @@ impl OperatorError for EndpointExplorationError {
                 "Verify endpoint network reachability and that the BMC Redfish service is listening.",
             ),
             EndpointExplorationError::UnsupportedVendor { .. }
-            | EndpointExplorationError::MissingVendor => Some(
+            | EndpointExplorationError::MissingVendor { .. } => Some(
                 "Confirm the endpoint's BMC vendor and model are listed in the NICo Hardware \
                  Compatibility List \
                  (https://docs.nvidia.com/infra-controller/documentation/reference/hardware-compatibility-list); \
@@ -2468,7 +2468,7 @@ mod tests {
                 EndpointExplorationError::UnsupportedVendor {
                     vendor: "unknown".to_string(),
                 } => true,
-                EndpointExplorationError::MissingVendor => true,
+                EndpointExplorationError::MissingVendor { observed: None } => true,
             }
         );
     }

crates/rpc/src/model/site_explorer.rs

@@ -426,7 +426,7 @@ mod tests {
 
     #[test]
     fn endpoint_report_propagates_operator_error_schema_to_rpc() {
-        let error = EndpointExplorationError::MissingVendor;
+        let error = EndpointExplorationError::MissingVendor { observed: None };
         let expected_schema = error.operator_error_schema();
 
         let report =